Pneumatic cushion



R. B. MILLER PNEUMATIC CUSHION Feb. 16, 1965 Filed July 20, 1962 20 FIG. --I

FIG-4 INVEN TOR. RUSSELL B. M/LLER (fla /4% ATTORNEYS United States Patent 3,169,756 PNEUMATIC CUSI-HGN Russell Miller, Akron, Ohio, assignor to Barbarian Plastics Products, Inc., Barberton, Ohio, a corporation of Ohio Filed July 20, 1962, Ser. No. 211,270 3 Claims. (Cl. 267-1) plastic forming a hollow body portion which is pneumatically inflated, and the other plastic being relatively hard and stitf, and providing a backing for the first plastic and providing attaching flanges whereby the pneumatic cushion can be secured to an object to be cushioned.

Another object of the invention is the provision of an improved, readily practiced, rapid, and comparatively inexpensive method for producing the pneumatic cushion defined in the other objects of the invention.

The foregoing objects of the invention, and others which will become apparent as the description proceeds, are achieved by the provision of a pneumatic cushion made from two plastics of different softness, one plastic being relatively soft and flexible and formed as a hollow body of substantially half cylinder shape, the hollow body being inflated with air under pressure, the other plastic being relatively stiff and hard and having a flat portion integrally joined with the fiat side of the hollow body to hold it fiat even when inflated, and flanges integral with and on the flat portion and extending beyond the hollow body and being of the other plastic and relatively stiff and hard and whereby the cushion can be secured to any object to be cushioned. v

In terms of method the invention provides that method of making a pneumatic cushion which includes the steps of pouring gelable plastic into a hollow mold having the bottom of the cavity of channel shape and the top of the cavity of substantially half cylinder shape, the plastic being of a type to set relatively stiff and hard and in an amount to substantially fill the channel shape of the bottom of the cavity, heating the mold while stationary to gel but not fully set the plastic, pouring a measured charge less than that required to fill the remainder of the cavity and of a plastic which is relatively soft and flexible when set into the mold, heating the mold and rotating it on corripound axes to first gel and then set up the second plastic as a hollow body and to set up the first plastic, stopping the mold rotation, cooling the mold, removing the compound material article from the mold, inflating the hollow body with air through a hollow needle, and sealing the needle hole.

For a better understanding of the invention reference should be had to the accompanying drawings wherein FIG. 1 is a side elevation, partially broken away, of one embodiment of the cushion of the invention;

FIG. 2 is a cross-sectional view, taken substantially on line 2-2, of FIG. 1;

FIG. 3 is a cross-sectional view, on a somewhat reduced scale, of a mold employed in the method of the invention; and

FIG. 4 is a view similar to FIG. 2, but on a reduced scale, of a modification of the invention.

In the drawings, the numeral 10 indicates generally a pneumaticcushion having a hollow body portion 12 of substantially half cylinder shape and formed of a relativ ly soft and flexible plastic. In a typical embodiment of the invention, the hollow body 12 is made of a plastic having a Shore durometer hardness of Type A of about 78:5. The particular plastic employed is usually a vinyl plastisol although other plastics may be used including dispersions of vinyl resins plus acrylic monomers, polyethylene, and the like.

The hollow body 12 may be formed with one flat end 14 and one longitudinally curved end 16 so that the flat ends 14 of a pair of the pneumatic cushions can be butted together to form a longer cushion, should this be desired. Usually the pneumatic cushions 10 are made in several different lengths so that the particular length desired can be selected to best adapt the cushion to a particular job. The hollow half cylindrical body 12 has a flat bottom portion 18 having a wall thickness usually somewhat thinner than the wall thickness of the cylindrical portion of the body, and the hollow body 12 is inflated with gas or air under pressure to provide an excellent pneumatic cushioning action.

The flat end 14 of the form of the invention of FIG. 1 may be molded to extend slightly beyond the end of the channel-shaped portion 20. This insures a smooth, crackfree butting together of several of the cushions when used end to end.

As best seen in FIG. 2, formed integrally with the bottom of the hollow body 12 is a channel-shaped plastic portion 2% made of a relatively stiff and hard plastic. In a typical embodiment of the invention the channel-shaped portion 20 of the pneumatic cushion has a Shore durometer hardness of Type D of about 65:5. The plastic of the channel-shaped portion 20 should have an afiinity for g and an integral bonding action with the plastic of the hollow body 12, and normally the plastic of the channel portion 12 is the same as the plastic of the hollow body 12 but is compounded to provide the different hardness specified. For example, the soft plastic is a vinyl plastisol, and the harder plastic is a vinyl dispersion-acrylic monomer.

In any event, the fiat bottom 22 of the channel-shaped portion 20 is bonded integrally with or fused with the fiat bottom 18 of the hollow body 12, and the'flat bottom 22 is sufiiciently stiff and rigid so that the inflation of the hollow body 12 does not adversely or objectionably curve or round the flat bottom 22; Formed integrally with the fiat bottom 22 of the channel 20 are flanges 24 which extend tangentially of the cylindrical sides of the hollow body 12,'witl1 the flanges 24 serving as attaching means for securing the pneumatic cushion in place on a dock, or the like, to be cushioned.

In one specific embodiment of the invention the flanges 24 are spaced apart a distance such as to fit snugly over the sides of a two-by-four, the flanges 24 being secured to the sides of the two-by-four by screws, nails, adhesive, or the like.

The embodiment of the invention illustrated in FIG. 4 includes a hollow body 12a of relatively soft and flexible plastic, again of a half cylindrical shape, this body being integrally bonded or fused to a fiat base portion 29a having integral attaching flanges 24a lying in the plane of the flat base portion 20a. .The flat base portion 20a and the flanges 24a are formed of a relatively hard and stiff plastic, such as has been previously described.

In the performance of the method of the invention, this is normally done with the aid of a mold indicated generally by the numeral 30 in FIG. 3. The mold 39 is of metal and has a cavity 32 having an upper portion 34 of half or substantially half cylindrical shape and a lower portion which is relatively Hat, and which-may be provided with longitudinally extending grooves 38 for forming the flanges 24 of the pneumatic cushion ot FIG. 2Q

these halves being, releasably secured together by screws 40. The mold is also provided with a removable screw plug, 42 which allows'the introduction of plastic materials The mold 3t? is normally made in two halves, as illustrated,

into the mold even when the mold parts are held together l by the screws 40. In the method of the invention with the mold closed'by the screws 40 the screw'plug' t-Z is removed and a sufiicient quantity of plastic is poured into V the mold to substantially fill the mold to the line 4%. This hard. Heat is now applied to the mold as to cause the plastic filling the mold to the line 44 to gel. During the application of heat the mold 3 is held stationary. With,

the plastic filling the'mold to the line 44 gelled, additional plastic is now poured into the mold 3.6. through the opening for the screw plug 42, and this plastic is of the type which sets up to be relatively soft "and flexible; The i plastic is of the type which sets up relatively stiff and amount of plastic introduced into the mold is less than i the remaining cavity of the mold and is in an amount sufiicient to] form the hollow body portion of the pneumatic cushion. The screw plug 42 is now returned to the mold to close it, and the mold 36 is now heated and at the same time is rotatedon comp'oundaxes to distribute the second plastic over the interior surface of the mold ,cavity'and over the exposed surface of the gelled hard plastic. Heat and rotation are continued until the second soft plastic is first gelled andthen finally fused or set up and the first plastic is likewise set up whereupon rotation of the mold is stopped, the mold is cooled, the screws 400i the mold are removed andthe'rnold is'opened and the pneumatic cushionis removed.

,Air under pressure is now introduced to the inside of the hollow body portion'of the pneumatic cushion, usually by means of a hollow needle, and the needle hole is sealed. a The pneumatic cushion produced by the method described provides a pneumaticcushion which appears to tion.

V/hat-isclaimed is:

U 1. A pneurnaticcushionadaptedlto be secured to a dock and the like and including a channel-shaped base of relative stiff and hardiviriylplastisolhaving aShorefdurometer hardnessof Type D of abouto i5 a hollow closed, fluid impervious relatively soft and fiexible body of vinyl plastisol and having a' Shore durorneter hardness of Type-A of about 78:5 and of substantially a half cylinder shape, the fiat side of'the half cylinder body' being thinner in wall thickness than the half cylinderwall thereof and being integrally bonded to the upper side of the channel-shaped base so that the outer surfaces of the fianges' of the channel-shaped ibase are'substantially tangent to the sides of the half cylinder body to be attached to a surface to be cushioned,'the soft and flexible body of plastic being internally inflated with gas under pressureto provide. pneumatic cushioning of objects striking thereagainst, and with at least one ei d'of the soft and flexible body being rounded longitudinally.

2. A pneumatic cushion made from two plastics of different softness, one plastic being relatively soft and flexbe and which is an integral one-piecerplastic member, but i which has certain portions of the plastic which are relatively still and hard, these portions being adaptedto secure the pneumatic cushion to an object to be cushioned,

and with other portions of, the pneumatic cushion being relatively soft and flexible and internally/inflated so as'to provide the desired cushioning action.

. The term set up, as employed in the specification and i claims, is intended to'cover the curing or fusing of the material molded to form the desired finished product upon cooling and removal from the mold.

While a certain representative. embodiment and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be madetlierein ible and formed as a hollow closed fluid impervious body of substantially half eylinder'shape, the hollow body being i inflated with air under pressure, the other plastic being relatively stilt and hard and having a fiat portion molded in integral relation with the fiat side of the hollow body to hold it fiat even'wheniniiated, and flanges integralwith and on the fiat portion and extending in the same plane as the flat portion beyond theh'oliow body and being of the other plastic-and relatively stiff iand'hard and whereby the flanges of the fiat portion of the cushion can be secured to any object to be cushioned as the fiat portion is placed in adjacent relation thereto. 7

3. A pneumatic cushion-according to claim 2 where the relatively soft plastic is a vinyl 'pla stisol havingfa Shore .durometer hardness of Type A of about 78:5 and where the'r elatively stifi and hard plastic is a vinyl fdispersion-- acrylic monomer having a Shore durometer hardness of 7 Type Dfof about :5, and where the plastics are integrally fused together in the presence of heat.

I References tilted in the fileJot this patent I UNITED STATES PATENTS i 1,666,234

without departingfrom the: spirit or scope of the inven-' i 

2. A PNEUMATIC CUSHION MADE FROM TWO PLASTIC SOF DIFFERENT SOFNESS, ONE PLASTIC BEING RELATIVELY SOFT AND FLEXIBLE AND FORMED AS A HOLLOW CLOSED FLUID IMPERVIOUS BODY OF SUBSTANTIALLY HALF CYLINDER SHPAE, THE HOLLOW BODY BEING INFLATED WITH AIR UNDER PRESSURE, THE OTHER PLASTIC BEING RELATIVELY STIFF AND HARD AND HAVING A FLAT PORTION MOLDED IN INTEGRAL RELATION WITH THE FLAT SIDE OF THE HOLLOW BODY TO HOLD IT FLAT EVEN WHEN INFLATED, AND FLANGES INTEGRAL WITH AND ON THE FLAT PORTION AND EXTENDING IN THE SAME PLANE AS THE FLAT PORTION BEYOND THE HOLLOW BODY AND BEING OF THE OTHER PLASTIC AND RELATIVELY STIFF AND HARD AND WHEREBY THE FLANGES OF THE FLAT PORTION OF THE CUSHION CAN BE SECURED TO ANY OBJECT TO BE CUSHIONED AS THE FLAT PORTION IS PLACED IN ADJACENT RELATION THERETO. 